Figure 3

Cytoreductive surgery restores effectiveness of immunotherapy even when administered in advanced tumor burden. (A) Mice (n = 10) bearing large established tumors were randomized to AdV-tk/GCV or Ad.LacZ/GCV; two days following completion mice underwent positive margin surgery. Recurrent flank tumors were observed. We observed dramatic decreases in recurrent tumor volumes in those mice receiving neoadjuvant AdV-tk/GCV. (B) Similarly, mice (n = 10) bearing established tumors were randomized to Ad.IFNα or Ad.LacZ, followed by partial resection surgery 3 days later. Again, recurrent tumors were decreased in mice receiving intratumoral immunotherapy protocols. (C) We next tested this approach in the setting of metastatic disease. Mice (n = 14) bearing established LKR tumors were administered AdV-tk/GCV or Ad.LacZ/GCV at a time when metastatic lesions were known to be present. Two days after completion of drug administration, complete tumor excision was completed. On Day 40 of the experiment, lung tumor burden was assessed. Mice randomized immunotherapy had significantly less metastatic disease as compared to mice receiving control treatment. * Represents a p < 0.05, ** represents a p < 0.01.